A little tip: When you are running Skype, if you exit, it will remain in the taskbar on the bottom right and in the ribbon bar. Even if you press the X button to close it. That is not normal as when you press X, it has to exit the main window but remain in the taskbar.

To fix this, just close Skype, then go to the Skype Shortcut, right click on it, then choose the compatibility tab, then choose Vista